Strander



May 19, 1964 R. L. zwoLiNskl `la'rAL 3,133,402

smANDER Filed April 12, 1962 2 sheets-sheet 1 Fig. l

INVENTORS ROBERT L.ZWOLINSK| .l ROY E. CORRALL May 19, 1964 R. l..zwoLlNsKl ETAL STRANDER 2 Sheets-Sheet 2 Filed April 12, 1962 INVENTOR-ROBERT LzwoLmsKl Rov CORR/n.1.

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3,133,402 SIRANDER Robert lL. Zwollnski, Stony Point, and Roy E.Corrall,

Franklin Square, N.Y., assiguors to Anaconda Wire and Cable CompanyFiled Apr. 12, 1962, Ser. No. 186,939 6 Claims. (Cl. 57-34) Ourinvention relates to strand twisting apparatus and part1cularly toapparatus for imparting a false twist to advanctng strands.

In the manufacture of cables such as electric cables made up of aplurality of strands such as insulated conductors 1t has become known tocable the strands with a false or alternating twist rather than twistthem in a continuous helix. This has the advantage that it can beaccomplished at high speed with light-weight equipment, but even more1mportant the cabling operation can be a continuous intermediary processof a more complex operation. This follows from the fact that theapplication of a false twist to advancingr strands does not require aseparate reeling or unreeling step.

It has, however, been a shortcoming of known apparatus for applying afalse twist that the twisting angle isV severely limited, usually to 180or less due to the Vfact that the lay plate by means of which the twistis imparted necessarily twists the strands both upstream and downstream,and the upstream twist, if it is too great, tangles ttlle strands andprevents them from advancing through the p ate.

We have discovered that upstream tangles in advancing strand can beprevented by applying the twist in graduated steps, and have inventedapparatus twisting advancing strands, comprising means for advancing aplurality of strands, irst means imparting a false twist of a selectedangle to the strands and second means mounted upstream of the firstmeans imparting a twist to the strands. The twist imparted by the secondmeans is in the same direction but of lesser angle than the false twistimparted by the iirst means.

Instead of a single means we may have a plurality of twisting meansupstream of the first means.V These means are mounted at consecutivestations and impart consecutively lesser angles of twist to the strandas they are removed from the lirst means. A second means isadvantageously mounted upstream of the iirst means restraining thestrands from rotation, with the angle of twist imparted by each of aplurality of intermediate twisting means being proportional to itsdistance from the second means.

Advantageously the twisting and restraining means may be lay platesrigidly mounted on a torsion bar.

A more thorough understanding of our invention may be obtained byreferring to the appended drawing.

In the drawing:

FIGURE 1 is a partially sectionalized side view of an apparatus of ourinvention.

FIGURE 2 is a plan view of the apparatus of FIG- URE 1.

Referring to the figures an apparatus indicated generally by the numeral10 applies a false or reverse twist to a plurality of strands 11. Thestrands 11 are formed into a cable 12 by a forming die 13 and cable 12is continuously advanced by means not shown, thereby also advancing thestrands 11 through the apparatus 10. In the apparatus 10 a verticalplate 14 is rigidly mounted on a base plate 16 by means of brackets 17,18. Downstream of the plate 14 another plate 15 is also rigidly mountedto the base 16 by means of brackets 19, 20. A die holder 21 which holdsthe forming die 13 is welded to the plate 15. The die holder 21 supportsthe inner race 22 of a ball bearing 23 on which a sprocket 24 attachedto a plate 26 is free to rotate, driven through a timing belt 25 bydrive 3,133,402. Patented May 19, 1964 ICC means not shown. The plate 26forms the end portion of a rigid frame 27 with an opposing lay plate 28held to the frame 27 by means of welded rods 29, 30, 31,32. The layplate is pierced by a plurality of openings 33 for the passage of thestrands 11.

Y The lay plate 28 is rigidly clamped to a torsion bar 34 made up offour square steel rods 36, 37, 38, 39 by means of a hub 41 and clampring 42. The hub 41 is locked on Vthe composite bar 34 by turning bolts43, 43 which thread into the ring 42. Spaced at equal distances betweenthe plates 28 and 14 are two additional lay plates 44, 45 eachperforated to match the perforations in the plate 28. These plates arelocked to the bar 34 by hub and ring clamps 46, 47 of the type used forthe plate 28, and a fourth perforated plate 48 is bolted to the plate 14in line with the plates 45, 44, 28. The plate 48 has a slide lit onbolts 49, 50, 51, 52 and is held against the plate 14 by compressionsprings 53, 54, 55, 56. The plate 14 has a central hole 57 of diametergreat enough to encompass the area of the perforations in the plate 48which match those in the plate 28. The plate 48 is also locked to thetorsion bar 34 by means of a hub and clamp 58. The bolts and springs49-54 restrain the plate 48 from rotation but permit it to movehorizontally to compensate for any shortening of the bar 34 when it istwisted.

The bar 34 is iixed on one end to the stationary plate 48 and on theother to the4 oscillating plate 28 which causes the rod to twist withthe degree of twisting of any section proportional to its distance fromthe plate 48. The plates 45, 44 are clamped to the bar 34 and they arecaused to twist through an angle depending upon `the angular twist inthe bar at the section to which they are clamped. In the ligures theplate 28 hasbeen twisted clockwise of the plate 48 and strands 59, 60are selected from the strands 11 to illustrate the path taken throughour apparatus. The perforations 33 in the plate 28 and, similarly, theperforations in the plates 44, 45 are advantageously lined with ceramicbushings 56 to reduce Vthe wear on the plates and abrasion of thestrands. If

the bushings are omitted the perforations 33 will, in any event, behighly polished with rounded edges. In the manufacture of telephonecables for which our apparatus is particularly useful it is usual toform cable cores of 25 conductor-pairs and the lay plates 48, 45, 44, 28will have at least 25 strand guide holes 33 with 25 pairs of cablesbeing stranded therethrough.

In the absence of the plates 44, 45 vthe strands 59, 60 would rubagainst each other at a point midway between the plates 48 and 28 whenthe plate 28 had turned 180 'as shown in the drawing. In addition thestrand 59 would abrade against all the other strands as it advanced. Infact, each of the strands would have a point of abrasion against each ofthe others and, of course, if the plate 28 were turned more than 180,the tangle of the strands upstream of the plate 28 would rapidly becomeunmanageable.

In our apparatus the strands 59 and 60 do not touch each other or anyother of the strands 11 and make contact only with the polished ceramicbushings 56. The perforations in the plates are selected on a minimumradius that will also assure that all strands remain clear of the bar 34and the clamps 46, 47, 42. Although we have illustrated an apparatus inwhich the plate 28 is oscillated through an angle of 180 in eitherdirection for a total lay-twist of 360 and have provided the twointermediate plates 44, 45 it will be understood that the plate 28 mightreadily be rotated through a lesser or greater angle and that additionallay plates, or only one, may be clamped on the bar 34 within the scopeof our invention.

Generally speaking, the greater the angle of oscillation applied to theplate-28 the greater will be the number of intermediate lay plates thatare necessary to prevent upstream tangles and, of course, if the angleof twist is small enough, no intermediate plates at all will be neededand our invention will not be applicable. We believe that wherehalf-twists of 90 or more are applied at least one intermediate plate isuseful since this will help reduce tangles due to slack that mayaccumulate in the strands and whipping action when the apparatus isoperated at high speed.

The torsion bar combination that we have invented is a convenient andinexpensive means of obtaining proportional degrees of twist in theintermediate lay plates of our invention, but it will be understood thatthe plates 44, 45, 28 might be mounted on bearings and oscillated bymeans of belts or chains around their peripheries and driven by wheelsor sprockets having diameters selected to give the appropriate angle ofrotation.

We have invented a new and useful apparatus for which we desire an awardof Letters Patent.

We claim:

1. Apparatus for twisting advancing strands to form a false-twistedcable, comprising:

(A) first means for imparting a false twist of a selected angle to saidstrands, and

(B) a plurality of twisting means mounted at consecutive stationsupstream of said first means,

(C) said twisting means imparting consecutively lesser angles of twistto said strands as said twisting means are removed from said firstmeans.

2. Apparatus for twisting advancing strands to form a false-twistedcable, comprising:

(A) first means for imparting a false twist of a selected angle to saidstrands,

(B) second means upstream of said first means for restraining saidstrands from twisting, and

(C) a plurality of twisting means mounted between said first and saidsecond means,

(D) each of said twisting means imparting a twist to said strandsproportional to its distance from said second means.

3. Apparatus for twisting advancing strands, comprising:

(A) a first perforated lay plate mounted in the path of said strandsimparting a false twist thereto,

(B) means for oscillating said lay plate through a selected angle,

(C) a stationary perforated lay plate mounted upstream of said firstplate,

(D) a torsion bar rigidly attached to said first and said stationaryplates,

(E) at least one intermediate perforated lay plate rigidly attached tosaid torsion bar between said first and said stationary lay plates, saidtorsion bar imparting a twist to said intermediate plate proportional toits distance from said stationary plate.

4. Apparatus for twisting advancing strands, comprising:

(A) a first lay plate mounted in the path of said strands imparting afalse twist thereto,

(B) means for oscillating said lay plate through a selected angle,

(C) a plurality of lay plates mounted at spaced intervals in the path ofsaid strands upstream of said first plate,

(D) means for oscillating each of said plurality of plates through anangle dependent on its distance from said first plate.

5. Apparatus for twisting advancing strands, compris- (A) a firstperforated lay plate mounted in the path of said strands imparting afalse twist thereto,

(B) means oscillating said lay plate through a selected angle,

(C) a stationary perforated lay plate mounted in the path of saidstrands upstream of said first plate,

(D) at least one intermediate perforated lay plate mounted in the pathof said strands between said first plate and said stationary plate, and

(E) means oscillating said intermediate plate at an angle less than theangle of oscillation of said first plate.

6. Apparatus for twisting advancing strands, compris- (A) a firstperforated lay plate mounted in the path of said strands imparting afalse twist thereto,

(B) means oscillating said lay plate through a selected angle,

(C) a stationary perforated lay plate mounted in the path of saidstrands upstream of said first plate,

(D) at least one intermediate perforated lay plate mounted in the pathof said strands between said first plate and said stationary plate, and

(E) means oscillating said intermediate plate at an angle less than theangle of oscillation of said first plate in proportion to its distancefrom said stationary plate.

References Cited in the file of this patent UNITED STATES PATENTS1,942,218 Schmitz Jan. 2, 1934 2,058,234 Johannessen Oct. 20, 19362,412,196 Ashbaugh'et al. Dec. 10, 1946 2,990,672 Demmel July 4, 1961FOREIGN PATENTS 885,159 Great Britain Dec. 20, 1961

2. APPARATUS FOR TWISTING ADVANCING STRANDS TO FORM A FALSE-TWISTEDCABLE, COMPRISING: (A) FIRST MEANS FOR IMPARTING A FALSE TWIST OF ASELECTED ANGLE TO SAID STRANDS, (B) SECOND UPSTREAM SAID FIRST MEANS FORRESTRAINING SAID STRANDS FROM TWISTING, AND (C) A PLURALITY OF TWISTINGMEANS MOUNTED BETWEEN SAID FIRST AND SAID SECOND MEANS, (D) EACH OF SAIDTWISING MEANS IMPARTING A TWIST TO SAID STRANDS PROPORTIONAL TO ITSDISTANCE FROM SAID SECOND MEANS.